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 * Copyright (c) 1997, 2006, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
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package javax.swing;

import javax.swing.event.*;

/**
 * This interface represents the current state of the
 * selection for any of the components that display a
 * list of values with stable indices.  The selection is
 * modeled as a set of intervals, each interval represents
 * a contiguous range of selected list elements.
 * The methods for modifying the set of selected intervals
 * all take a pair of indices, index0 and index1, that represent
 * a closed interval, i.e. the interval includes both index0 and
 * index1.
 *
 * @author Hans Muller
 * @author Philip Milne
 * @see DefaultListSelectionModel
 */

public interface ListSelectionModel {

  /**
   * A value for the selectionMode property: select one list index
   * at a time.
   *
   * @see #setSelectionMode
   */
  int SINGLE_SELECTION = 0;

  /**
   * A value for the selectionMode property: select one contiguous
   * range of indices at a time.
   *
   * @see #setSelectionMode
   */
  int SINGLE_INTERVAL_SELECTION = 1;

  /**
   * A value for the selectionMode property: select one or more
   * contiguous ranges of indices at a time.
   *
   * @see #setSelectionMode
   */
  int MULTIPLE_INTERVAL_SELECTION = 2;


  /**
   * Changes the selection to be between {@code index0} and {@code index1}
   * inclusive. {@code index0} doesn't have to be less than or equal to
   * {@code index1}.
   * <p>
   * In {@code SINGLE_SELECTION} selection mode, only the second index
   * is used.
   * <p>
   * If this represents a change to the current selection, then each
   * {@code ListSelectionListener} is notified of the change.
   *
   * @param index0 one end of the interval.
   * @param index1 other end of the interval
   * @see #addListSelectionListener
   */
  void setSelectionInterval(int index0, int index1);


  /**
   * Changes the selection to be the set union of the current selection
   * and the indices between {@code index0} and {@code index1} inclusive.
   * {@code index0} doesn't have to be less than or equal to {@code index1}.
   * <p>
   * In {@code SINGLE_SELECTION} selection mode, this is equivalent
   * to calling {@code setSelectionInterval}, and only the second index
   * is used. In {@code SINGLE_INTERVAL_SELECTION} selection mode, this
   * method behaves like {@code setSelectionInterval}, unless the given
   * interval is immediately adjacent to or overlaps the existing selection,
   * and can therefore be used to grow the selection.
   * <p>
   * If this represents a change to the current selection, then each
   * {@code ListSelectionListener} is notified of the change.
   *
   * @param index0 one end of the interval.
   * @param index1 other end of the interval
   * @see #addListSelectionListener
   * @see #setSelectionInterval
   */
  void addSelectionInterval(int index0, int index1);


  /**
   * Changes the selection to be the set difference of the current selection
   * and the indices between {@code index0} and {@code index1} inclusive.
   * {@code index0} doesn't have to be less than or equal to {@code index1}.
   * <p>
   * In {@code SINGLE_INTERVAL_SELECTION} selection mode, if the removal
   * would produce two disjoint selections, the removal is extended through
   * the greater end of the selection. For example, if the selection is
   * {@code 0-10} and you supply indices {@code 5,6} (in any order) the
   * resulting selection is {@code 0-4}.
   * <p>
   * If this represents a change to the current selection, then each
   * {@code ListSelectionListener} is notified of the change.
   *
   * @param index0 one end of the interval.
   * @param index1 other end of the interval
   * @see #addListSelectionListener
   */
  void removeSelectionInterval(int index0, int index1);


  /**
   * Returns the first selected index or -1 if the selection is empty.
   */
  int getMinSelectionIndex();


  /**
   * Returns the last selected index or -1 if the selection is empty.
   */
  int getMaxSelectionIndex();


  /**
   * Returns true if the specified index is selected.
   */
  boolean isSelectedIndex(int index);


  /**
   * Return the first index argument from the most recent call to
   * setSelectionInterval(), addSelectionInterval() or removeSelectionInterval().
   * The most recent index0 is considered the "anchor" and the most recent
   * index1 is considered the "lead".  Some interfaces display these
   * indices specially, e.g. Windows95 displays the lead index with a
   * dotted yellow outline.
   *
   * @see #getLeadSelectionIndex
   * @see #setSelectionInterval
   * @see #addSelectionInterval
   */
  int getAnchorSelectionIndex();


  /**
   * Set the anchor selection index.
   *
   * @see #getAnchorSelectionIndex
   */
  void setAnchorSelectionIndex(int index);


  /**
   * Return the second index argument from the most recent call to
   * setSelectionInterval(), addSelectionInterval() or removeSelectionInterval().
   *
   * @see #getAnchorSelectionIndex
   * @see #setSelectionInterval
   * @see #addSelectionInterval
   */
  int getLeadSelectionIndex();

  /**
   * Set the lead selection index.
   *
   * @see #getLeadSelectionIndex
   */
  void setLeadSelectionIndex(int index);

  /**
   * Change the selection to the empty set.  If this represents
   * a change to the current selection then notify each ListSelectionListener.
   *
   * @see #addListSelectionListener
   */
  void clearSelection();

  /**
   * Returns true if no indices are selected.
   */
  boolean isSelectionEmpty();

  /**
   * Insert length indices beginning before/after index.  This is typically
   * called to sync the selection model with a corresponding change
   * in the data model.
   */
  void insertIndexInterval(int index, int length, boolean before);

  /**
   * Remove the indices in the interval index0,index1 (inclusive) from
   * the selection model.  This is typically called to sync the selection
   * model width a corresponding change in the data model.
   */
  void removeIndexInterval(int index0, int index1);

  /**
   * Sets the {@code valueIsAdjusting} property, which indicates whether
   * or not upcoming selection changes should be considered part of a single
   * change. The value of this property is used to initialize the
   * {@code valueIsAdjusting} property of the {@code ListSelectionEvent}s that
   * are generated.
   * <p>
   * For example, if the selection is being updated in response to a user
   * drag, this property can be set to {@code true} when the drag is initiated
   * and set to {@code false} when the drag is finished. During the drag,
   * listeners receive events with a {@code valueIsAdjusting} property
   * set to {@code true}. At the end of the drag, when the change is
   * finalized, listeners receive an event with the value set to {@code false}.
   * Listeners can use this pattern if they wish to update only when a change
   * has been finalized.
   * <p>
   * Setting this property to {@code true} begins a series of changes that
   * is to be considered part of a single change. When the property is changed
   * back to {@code false}, an event is sent out characterizing the entire
   * selection change (if there was one), with the event's
   * {@code valueIsAdjusting} property set to {@code false}.
   *
   * @param valueIsAdjusting the new value of the property
   * @see #getValueIsAdjusting
   * @see javax.swing.event.ListSelectionEvent#getValueIsAdjusting
   */
  void setValueIsAdjusting(boolean valueIsAdjusting);

  /**
   * Returns {@code true} if the selection is undergoing a series of changes.
   *
   * @return true if the selection is undergoing a series of changes
   * @see #setValueIsAdjusting
   */
  boolean getValueIsAdjusting();

  /**
   * Sets the selection mode. The following list describes the accepted
   * selection modes:
   * <ul>
   * <li>{@code ListSelectionModel.SINGLE_SELECTION} -
   * Only one list index can be selected at a time. In this mode,
   * {@code setSelectionInterval} and {@code addSelectionInterval} are
   * equivalent, both replacing the current selection with the index
   * represented by the second argument (the "lead").
   * <li>{@code ListSelectionModel.SINGLE_INTERVAL_SELECTION} -
   * Only one contiguous interval can be selected at a time.
   * In this mode, {@code addSelectionInterval} behaves like
   * {@code setSelectionInterval} (replacing the current selection),
   * unless the given interval is immediately adjacent to or overlaps
   * the existing selection, and can therefore be used to grow it.
   * <li>{@code ListSelectionModel.MULTIPLE_INTERVAL_SELECTION} -
   * In this mode, there's no restriction on what can be selected.
   * </ul>
   *
   * @throws IllegalArgumentException if the selection mode isn't one of those allowed
   * @see #getSelectionMode
   */
  void setSelectionMode(int selectionMode);

  /**
   * Returns the current selection mode.
   *
   * @return the current selection mode
   * @see #setSelectionMode
   */
  int getSelectionMode();

  /**
   * Add a listener to the list that's notified each time a change
   * to the selection occurs.
   *
   * @param x the ListSelectionListener
   * @see #removeListSelectionListener
   * @see #setSelectionInterval
   * @see #addSelectionInterval
   * @see #removeSelectionInterval
   * @see #clearSelection
   * @see #insertIndexInterval
   * @see #removeIndexInterval
   */
  void addListSelectionListener(ListSelectionListener x);

  /**
   * Remove a listener from the list that's notified each time a
   * change to the selection occurs.
   *
   * @param x the ListSelectionListener
   * @see #addListSelectionListener
   */
  void removeListSelectionListener(ListSelectionListener x);
}
